Existing iris scanners can be deceived by pictures of other people's irises. I do not doubt that facial recognition will be fooled by people making masks (to fool infrared scanning).
The basic principle of biometric reading is the equivalent to sliding your photo under the door to a guard. The guard checks the photo against an already existing set of photos and lets you in. They don't check that the photo is of you - which is a common failing when you let marketing design your security.
http://www.schneier.com/blog/archives/2012/07/fake_irises_fo...
http://www.bbc.com/news/technology-18997580
The basic principle of biometric reading is the equivalent to sliding your photo under the door to a guard. The guard checks the photo against an already existing set of photos and lets you in. They don't check that the photo is of you - which is a common failing when you let marketing design your security.